The Syrian news agency SANA on April 30 quoted a military source as saying positions in the provinces of Hama and Aleppo had been "subjected to a new aggression with hostile missiles."

The Syrian Observatory for Human Rights, based in Britain, says the attack appears to have been carried out by Israel and that it also targeted an arms depot for surface-to-surface missiles at a base in northern Syria known as Brigade 47. The Observatory says four Syrians were also among casualties.

The government in Tehran has sent thousands of fighters to back Syrian President Bashar al-Assad's forces in a seven-year civil war.